1. Technical Field
The invention relates to a device comprising a flow cell defining a treatment region that contains a treatment location that extends along a plane for the chemical or electrolytic surface treatment of plate-shaped articles at the treatment location, when a main plane of the articles extends along the plane along which the treatment location extends, with first feed elements in the form of tubes with outlet openings for the directed supply of a process liquid to the treatment region.
The basic aim in connection with surface treatment devices, for example galvanic baths, which are used for coating plate-like articles, for example printed circuit boards, is to achieve an even surface quality, for example a good distribution of the layer density over the total surface of the plate to be coated. In the case of printed circuit boards the drilled holes are particularly critical, whose interior walls should also possibly be provided with a layer density which should come as close as possible to the average copper layer density in the area of the surface.
2. Prior Art
A further aim generally is to intensify and accelerate the effects of the electrolytical or chemical processes, i.e. the deposition in a galvanic bath, as a whole, wherein it is part of the prior art in connection with galvanic baths (for example DE 44 05 741) to move the electrolyte past the printed circuit boards to be coated in the galvanic bath by means of suitable pipe arrangements in order to achieve a greater deposition speed. However, with the increasing effect of this principle, the pump outlay for the forced passage of the electrolyte through the galvanic bath is increased to uneconomical sizes. Further than that, the increased pump energy outlay leads to increasing heat development, which shows its effects in an increased heat supply to the galvanic bath, whose removal again requires additional energy outlays.
A further concept for intensifying and accelerating the processes in the galvanic bath which, for example, is used for the coating of printed circuit boards, is known from EP 0 420 640 A1; based on the known effect that a moving electrolyte permits cathode current densities of two to three times those of a non-moving electrolyte, it is proposed there to conduct air bubbles along both sides of the article to be coated, which emerge from a container below the galvanic bath and result in the desired movement effect. However, in the device described there the air bubbles are essentially used for achieving a recirculating effect in the electrolyte liquid in such a way, that the electrolyte liquid rises along the article to be coated and drops down again in the wall areas of the electrolyte container, after which the cycle starts again.